Ok. Serious business here. I found a 1yr old lonely Cayuga drake abandoned at the humane society (freaking Pyxis!)
Question: Do I need to quarantine him 30days like a chicken???

So the good news here is that ducks don't carry nearly as many nasty diseases as chickens do - of the respiratory diseases, they carry only mycoplasma. They also can carry diseases that affect other ducks, but not so much chickens.
That said, quarantining is always best practice. I'd probably want to quarantine him for two weeks or so to be safe.